A carbon heat source of this type is manufactured in the following procedure:
First, carbon powder, a burning adjustment agent, and a binder (water) are kneaded to produce a kneaded mixture, and the kneaded mixture is caused to undergo a continuous extrusion molding process to form a cylindrical, carbon heat source rod (see paragraph 0003 of Patent Document 1). The carbon heat source rod immediately after the molding process contains at least 20 wt % of water that ensures sufficient formability of the carbon heat source rod, that is, sufficient fluidity of the kneaded mixture.
Thereafter, in the process of transporting the carbon heat source rod, the carbon heat source rod is dried with a blast of hot air (see paragraphs 0019 to 0020 and FIG. 1 of Patent Document 1), and the dried carbon heat source rod is cut into a carbon heat source having a predetermined length. A final target water content in the carbon heat source is 10 wt % or lower, and water content at this level sufficiently ensures ignitability of the carbon heat source.
On the other hand, the carbon heat source rod can be dried by using a far-infrared heater (see Patent Document 2) instead of blasting hot air described in Patent Document 1.